Technical Field
The present disclosure generally relates to light sources, and in particular, LED light sources
Description of the Related Art
Due to environmental and energy efficiency concerns, the lighting industry is in a current state of flux and working hard to develop a more efficient, yet equal quality, light source to replace traditional incandescent light sources. Traditional incandescent light sources are able to produce high lumen output, to which consumers have grown accustom. However, incandescent light sources generally suffer from poor power efficiency and short life span.
Several alternative light sources have been introduced in an effort to solve the energy efficiency and life span issues presented by traditional incandescent light sources. An example of an alternative light source is LED light sources. LED light sources have the potential to solve the energy efficiency and life span issues associated with incandescent light sources, but for more the most part, to date LED light sources have failed to replace incandescent light sources for the majority of the lighting market.
There are a variety of reasons why LED light sources have failed to effectively replace incandescent light sources. For example, one reason that LED light sources have not reached their potential is because LED light sources have strict heat management requirements. In particular, in order for LEDs to work efficiently, the heat generated by the LED itself must be managed very efficiently such that the operating temperature of the LED is minimized. If the LED is allowed to overheat, or run at too high of operating temperature, then the light output from the LED significantly decreases. In addition, if the LED overheats, then the life span and quality of light output decreases. Thus, light source developers have worked tirelessly at trying to develop heat management systems in LED light sources that are able to efficiently manage the heat produced by the LED.
The conventional method of managing the heat at generated by the LEDs in an LED light source includes the use of a heat sink. In particular, the LEDs are typically mounted to one or more heat sinks that are designed to pull the heat away from the LEDs. An example heat sink structure may include an LED mounted to a primary structure that is responsible for transferring heat directly away from the LED. The primary structure is then mounted to a secondary structure that transfers the heat from the primary structure and eventually out of the light source structure itself.
The heat sinks in conventional LED light sources can include a relatively large finned-type structure that is located between the LEDs and the base (socket) of the light source. The heat sinks are conventionally made from metal, composite, or a similar material with good heat conduction properties. The size and type of materials used to create the heat sinks in conventional LED light sources create several disadvantages.
First, the size of the heat sinks in conventional LED lights sources may create a problem in that many LED light sources do not match the form factor of traditional incandescent bulbs. There are literally billions of light sockets installed worldwide, and any replacement light source to incandescent bulbs must have close to the same form factor as a standardized incandescent bulb. Due to the heat management requirements of LED light sources, the heat sinks are often relatively large, and therefore, many LED light sources do not have the same form factor as the traditional incandescent equivalent.
Second, at least partly due to the large amounts of metal used to create the heat sink structure in conventional LED light sources, the cost per LED light source is very high compared to an incandescent bulb. For example, at the time of filing this application a typical LED light source sold in home improvement retail centers cost about between ten to twenty times the cost of an incandescent bulb. The cost associated with manufacturing the heat sinks has stifled the ability of conventional LED light sources to become an affordable replacement option for the majority of consumers.
Third, the heat sink structures associated with conventional LED light sources produce a light source that has a poor aesthetic appearance. In essence, many conventional LED light sources look more like a machine than a decorative light source. Many consumers will not accept installing these types of LED light sources in light fixtures where the light source is visible due to the poor aesthetic appearance of conventional LED light sources.
In addition to all of the above disadvantages of heat sink structures in conventional LED light sources, most of the conventional heat sink structures are still unable to effectively manage the heat produced by the LEDs to allow a 60 W, 75 W or 100 W equivalent light source to be produced from an LED light source. Despite the bulky and expensive heat sink structures used on conventional heat sources, the light output of the LEDs are still not maximized because the LEDs will overheat, causing a loss in light output, shorter life span, and poor quality of light.
Accordingly, there is a need for a better heat management structure for LED light sources that maximizes the heat transfer away from the LEDs, fits traditional light socket form factors, costs less than conventional metal heat sink structures, and produces an aesthetically pleasing light source.